The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the inventors hereof, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure is directed to methods and apparatuses for directing a beam over a communication channel towards a receiving device (e.g., beamforming), and, more particularly, to computing compressed feedback information from which a transmission source can compute a steering matrix for the communications channel.
Beamforming is a signal processing technique used in systems for directional signal transmission or reception. Spatial selectivity may be achieved by using adaptive or fixed receive/transmit beam patterns. Beamforming takes advantage of constructive/destructive wave interference to change the direction of a beam. As defined herein, a beam is an electromagnetic wave that carries data to a receiver and that is formed by the constructive/destructive interference pattern of two or more waves transmitted by one or more antennas.
Traditionally, a receiving device receives a beam from the transmission source and computes a channel state matrix for the intended channel. The receiver transmits the channel state matrix back to the transmission source for modifying the shape of the transmitted beam. In other previous implementations, the receiver transmits feedback that includes a steering matrix or a compressed steering matrix from which a steering matrix can be calculated. The compressed steering matrix reduces the amount of data that must be sent by the receiver. However, computing the compressed steering matrix in previous methods involved additional processing computation beyond the computation of the steering matrix. Although these mechanisms for performing beamforming are effective, these systems are inefficient in the amount of data in the feedback to the transmission source or the amount of processing that is required to generate the feedback that is sent to the transmission source.